Sunday, October 21, 2012

Why was this hornet's nest so close to the ground?

Now that the leaves are all down, you can sometimes spot interesting things that were hidden during the summer.  Like this Bald-Faced Hornet's nest that has its opening less than a foot above the ground, which is probably why I couldn't find it earlier in the summer.   I knew there were hornets around because I saw them, but I was looking UP into the treetops, where these nests usually are.  And here there was a nest less than 30 feet from my chicken coop and practically ON the ground -- not more than six feet from where I was harvesting wild plums!  I probably walked past that nest dozens of times and never even knew it was there.  I didn't bother them and they didn't bother me.

Bald-faced Hornet
This is the second time I've found a very low nest on my land -- the first was only about 3 feet off the ground, near another outbuilding.  There are plenty of trees around here to nest in, so I am wondering:  Do hornets often build so low, or do I have an unusual strain of these insects breeding here?  Hornets only use the nest for one season, after which they all die off except the new queens, who hibernate over the winter, producing new colonies in the spring.  So it is conceivable that some mutation is causing queens here to nest low.  I'll have to watch for more low nests next spring.

Before I go any further, I should mention that there is NO HONEY in a nest like this, in spite of what Hollywood might think.  In both cartoons and live action films (such as in Doctor Doolittle 2, where a bear climbs up to a nest for honey) hornet's nests are mistakenly confused with old-fashioned garden beehives.  Climb up to one of these nests and all you will get is a bunch of stings, because hornets don't make honey.  They are predators that feed their larvae on  insects.

Back of my coop -- the lighter areas
are where the hornets scraped off
wood fibers for their nest.
Where were the hornets getting their wood fibers to make this nest?  From the back of my chicken coop, where they scraped the bare weathered wood clean.  I've seen this behavior here before, both with hornets and wasps, but wasn't paying much attention this summer because of the heat wave.  It wasn't until I found the nest that I went to look at the coop.  You can very clearly see the lighter areas where they were working (click the pix to enlarge).

Interestingly, they seem to follow the vertical lines of the boards.  In cases where I have actually seen hornets doing this, they are always clinging vertically, never horizontally. Most likely, they are following the grain of the wood.  And if you listen very closely, you can actually hear them chewing.  In fact, the first time I observed this behavior many years ago, it was by first hearing a strange scraping sound, looking for the source, then seeing a hornet busily chewing along a dead goldenrod stalk.

In this closeup,  you can clearly see where they left off and the patina of the old wood (darker area on the left) still shows.  When you look at the nest itself, you also see variations in the color of the paper, with clear stripes from both the dark and light areas.  This suggests to me that each wasp goes back to the same part of the coop wall, gets a load of fibers, then returns to the same area on the nest.  But since I have not actually observed this, it is only guesswork.

All of this brings up the question of where wasps and hornets get their wood fibers in developed areas.  An old weather-worn shack like my chicken coop would never be tolerated in more upscale neighborhoods.  Ditto for dead trees and other suitable debris.  Maybe they use wooden fences?  I have seen photos of nests that are more reddish in color, as if made from redwood.

Hornets, along with their cousins, the paper wasps, are very good for the garden -- which is where the inhabitants of this nest were hunting all summer.  I watched them searching among the broccoli and cabbage leaves for those little green caterpillars.  When they find one, they sting it and carry it back to their nest.  Ditto for army worms and other pests, including flies, which can be found in abundance around the coop and manure pile. Plus, both hornets and wasps visit flowers to eat pollen and nectar, and seem to be moving into the niche that has been vacated by honey bees around here.  I only saw two honey bees all summer, but lots of wasps were on the flowers, and we got a good harvest.  So unless the nests are someplace dangerous to me or my animals, I leave these very beneficial insects alone.   Besides, they give me an excellent reason NOT to paint the chicken coop!

Closeup of the nest after I collected it, showing the
variations of colors of wood pulp used.

4 comments:

cipher said...

How long will it take for the wood to regain its patina?

Robert said...

Are you sure they are not Tracker Jackers?

YonassanGershom said...

cipher, I have no idea -- probably a year or two.

YonassanGershom said...

LOL, Robert -- I had to look that one up, (I did not see "Hunger Games," the trailers did not interest me) but believe me, in the real world these ladies (yes, the workers are all female) can be vicious if you disturb their nests, and swarms WILL chase you. So the idea of mutated Tracker Jackers is feasible for dystopian future. No doubt they are called "Jackers" because hornets are really a type of arboreal Yellow Jacket.